Rub energetics of compressor blade tip seals

The rub mechanics of the abradable blade tip seals of aircraft gas turbine engine compressors were studied under simulated engine conditions. In twelve statistically planned instrumented rub tests using single titanium blades and fibermetal rubstrips, five basic rub parameters were varied to determine their effects on the rub energy, the heat split between the blade, rubstrip surface and rub debris and the blade and seal wear. The rub energies were found to be most significantly affected by the incursion rate while rub velocity and blade thickness were of secondary importance. In five additional rub tests using single nickel alloy blades and multiple titanium alloy blades, rub energy and wear effects were found to be similar for titanium and nickel alloy blades while rub energies increased for multiple blades relative to single-blade test results.